改错1.He need some help.2.Does he need come?3.He need not to come.

He needs some help
Does he need to come.
He need not come

1.He needs some help.
2.Does he need to come?
3.He don't need to come.
(你的问题在于：NEED情态动词和行为动词的区别没有弄清.看一下,下面的内容也许会帮助你区别NEED情态动词和行为动词)
一、作情态动词
1．need作情态动词无人称或数的变化,后接动词原形,多用于否定句和疑问句中.如：You needn't worry.你不必担心.
2．由need引出的一般疑问句,肯定回答常用must或have to;否定答语常用needn't.如：
—Need I answer the question?我需要回答那个问题吗?
—Yes,you must./Yes,you have to.是的,你必须回答./是的,你得回答./No,you needn't.不,不必了.
3．由must引出的一般疑问句,肯定回答用must,否定答语用needn't或don't have to.如：
—Must I do the work now?我必须现在干这个活吗?
—Yes,you must /have to.是的,你必须做./No,you needn't /don't have to.不,你现在不必做.
二、作行为动词
need 作为行为动词有人称和数的变化,后面可接名词、代词、动名词及带to 的动词不定式；可用于肯定句、疑问句和否定句中,如：She needs help.她需要帮助.I don't need to see the doctor.我不需要看病.—Do you need to go at once?你需要马上走吗?
—Yes,I do.是的,我得马上去.
—No,I don't.不,不用马上走.